The present invention relates to an image generation method, a program and an information storage medium.
In the real world, one may encounter a phenomenon in which when the external world is viewed through a camera having a lens sweated with a waterdrop of rain or plume, the exterior scene is reflected on the waterdrop under refraction of light.
If such a phenomenon is attained in generating an image in a virtual three-dimensional space, for example, in a game system, the refraction of light on a waterdrop can more realistically be represented.
If it is wanted to represent a waterdrop reflecting the external world thereon by faithfully simulating the refraction of light, however, a huge and complicated operation is required to compute and draw the external world to be reflected onto the waterdrop. It is therefore difficult that a game system or other hardware having a limited processing capacity generates images of a waterdrop by simulating the refraction of light in real time.
In addition, the manner of view relating to a waterdrop sweated on the camera lens is complicated variable under the influence of various factors such as changes in the angle of view, focusing and diaphragm of the camera.
A further complicated operation is required to simulate such complicated changes in real time.